Nomenclature:

Simple sugars have three-letter abbreviations for instance Glc (glucose), Gal (galactose), Man (mannose), Fuc (fucose). Sugar derivatives can also be abbreviated, like as GlcNAc   (N-acetylglucosamine), GalNAc   (N-acetylgalactosamine).  This   also permits an abbreviated form of description for sugars which are bonded together and the nature of the covalent bonds. Therefore, for instance, lactose can be represented as Galβ1 → 4Glc.